Chronic exposure to an extremely low-frequency magnetic field induces depression-like behavior and corticosterone secretion without enhancement of the hypothalamic-pituitary-adrenal axis in mice

Bioelectromagnetics. 2013 Jan;34(1):43-51. doi: 10.1002/bem.21743. Epub 2012 Jul 2.

Abstract

An extremely low-frequency magnetic field (ELF-MF) is generated by power lines and household electrical devices. Many studies have suggested an association between chronic ELF-MF exposure and anxiety and/or depression. The mechanism of these effects is assumed to be a stress response induced by ELF-MF exposure. However, this mechanism remains controversial. In the present study, we investigated whether chronic ELF-MF exposure (intensity, 1.5 mT; [corrected] total exposure, 200 h) affected emotional behavior and corticosterone synthesis in mice. ELF-MF-treated mice showed a significant increase in total immobility time in a forced swim test and showed latency to enter the light box in a light-dark transition test, compared with sham-treated (control) mice. Corticosterone secretion was significantly high in the ELF-MF-exposed mice; however, no changes were observed in the amount of the adrenocorticotropic hormone and the expression of genes related to stress response. Quantification of the mRNA levels of adrenal corticosteroid synthesis enzymes revealed a significant reduction in Cyp17a1 mRNA in the ELF-MF-exposed mice. Our findings suggest the possibility that high intensity and chronic exposure to ELF-MF induces an increase in corticosterone secretion, along with depression- and/or anxiety-like behavior, without enhancement of the hypothalamic-pituitary-adrenal axis.

MeSH terms

  • Adrenal Glands / radiation effects*
  • Adrenocorticotropic Hormone / blood
  • Animals
  • Behavior, Animal / radiation effects
  • Body Size / radiation effects
  • Corticosterone / blood
  • Corticosterone / metabolism*
  • Depression / blood
  • Depression / enzymology
  • Depression / etiology*
  • Depression / metabolism
  • Electromagnetic Fields / adverse effects*
  • Emotions / radiation effects
  • Gene Expression Regulation, Enzymologic / radiation effects
  • Hypothalamo-Hypophyseal System / radiation effects*
  • Male
  • Mice
  • Mice, Inbred ICR
  • Norepinephrine / blood
  • Time Factors
  • Tyrosine 3-Monooxygenase / genetics

Substances

  • Adrenocorticotropic Hormone
  • Tyrosine 3-Monooxygenase
  • Corticosterone
  • Norepinephrine